Specifications

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ALCOA MILL PRODUCTS
ALLOY 7150-T7751 PLATE
AND 7150-T77511 EXTRUSIONS
SUPERIOR COMBINATION OF HIGH STRENGTHGOOD CORROSION RESISTANCE
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ALLOY 7150-T7751 PLATE & 7150-T77511 EXTRUSIONS
M A J O R
B R E A K T H R O U G H
Alloy 7150-T77 provides an unsurpassed combination of high strength and corrosion resistance
compared to other 7XXX series aerospace alloys of similar strength. Alloy 7150-T77 provides peak
strength through the Alcoa-patented-T77 aging process.
C O R R O S I O N
R E S I S T A N C E
Alcoa guarantees an accelerated test exfoliation rating of EB or better for 7150-T7751 plate and
7150-T77511 extrusions, based on the 48-hour ASTM G34 EXCO test. This performance level
is equivalent to other 7XXX-series alloys in an “exfoliation resistant” -T76 condition.
The accompanying photographs display the results of long-term, aggressive seacoast atmospheric
exposure. T/2 plane specimens of 7150-T7751 plate display a typical behavior of “P” (pitting and
no exfoliation) after a 2 year, 11 month exposure. For comparison, T/2 plane specimens of similarstrength 7150-T6 plates are rated ED (severe exfoliation) after exposure of 2 years and 6 months.
This severe corrosion condition is not considered unusual for 7XXX-T6 alloys exposed at seacoast
for this duration.
Alloy 7150-T77 also provides good stress corrosion cracking resistance. When specified,
Alcoa will certify that 7150-T7751 plate and 7150-T77511 extrusions pass the 20-day alternate
immersion test per ASTM-G47 at 25 ksi (172 MPa) shor t transverse applied stress. Other
guarantees are subject to inquiry.
7150-T6X WORST CASE EXFOLIATION
2.5 years Exposure at Point Judith, R.I.
588027-7
7150-T7751 PLATE - 0.75 IN. THICK
2 years, 11 months
Point Judith, R.I.
Seacost Exposure
T/2
A P P L I C A T I O N S
T/2 PLANE, ED
S-547493-2 7150-T6151
I N
T/2 PLANE, ED
S-547526-2 7150-T651
S E R V I C E
Stiffened upper wing panels and lower horizontal stabilizer panels of Alloy 7150-T7751 plate and
7150-T77511 extrusions are now in service on numerous civil and military transport aircraft.
The alloy and temper are effective in compression-loaded stiffened panels requiring a combination
of high compressive yield strength, moderately high toughness, good fatigue and corrosion
resistance vs. stiffened panels made from earlier products such as 7150-T6 or 7075-T6.
Other successful applications of 7150-T77 include: extruded fuselage stringers, fuselage keel beams,
and airline passenger seal tracks.
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Alloy 7150-T77 provides weight savings opportunities in structure governed by static strength
requirements but where “overaged” condition corrosion resistance is required.
PROCUREMENT SPECIFICATIONS
Plate
Temper . . . . . . . . 7150-T7751
Specification . . . AMS 4252
MIL-HDBK-5
Coverage . . . . . . Approved
Extrusion
Temper . . . . . . . . 7150-T77511
Specification . . . AMS-4345
MIL-HDBK-5
Coverage . . . . . . Approved
“S”-BASIS MINIMUM LONGITUDINAL PROPERTY COMPARISONS
OF 1.001 INCH (25.2 MM) PLATE. UNITS: ksi (MPa)
Ultimate
Tensile
Alloy/Temper Strength
Tensile
Yield
Strength
7150-T7751
7150-T6151
7075-T651
7050-T7651
7075-T7651
78
78
69
67
59
84
84
76
77
70
(579)
(579)
(524)
(531)
(483)
Compressive
Yield
Strength
Elongation %
(538)
(538)
(476)
(462)
(407)
77
75
66
64
59
(531)
(517)
(455)
(441)
(407)
8
9
6
8
6
EXCO
Rating
EB
EC (Typ.)
ED (Typ.)
EB
EB
“S”-BASIS MINIMUM 7150-T7751 PLATE PROPERTIES
in. 0.250-0.499 0.500-0.749 0.750-1.000 1.001-1.500 1.501-3.000
mm (6.35-12.69) (12.70-19.04) (19.05-25.40) (25.41-38.10) (38.11-76.20)
Ultimate
Tensile
Strength
L
LT
ST
80 (552)
80 (552)
-
83 (572)
83 (572)
-
84 (579)
84 (579)
-
84 (579)
84 (579)
-
82 (565)
82 (565)
77 (531)
Tensile Yield
Strength
L
LT
ST
74 (510)
74 (510)
-
77 (531)
76 (524)
-
78 (538)
76 (531)
-
78 (538)
77 (531)
-
76 (524)
75 (517)
67 (462)
Compressive L
Yield Strength LT
73 (503)
77 (531)
76 (524)
79 (545)
77 (531)
81 (558)
77 (531)
81 (558)
75 (517)
79 (545)
Elongation % L
LT
ST
8
8
-
8
8
-
8
8
-
8
8
-
7
6
1
K lc , ksi √in .
(MPA √m )
-
-
20 (22.0)
18 (19.8)
22 (24.2)
20 (22.0)
inquire
inquire
L-T
T-L
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ALLOY 7150-T7751 PLATE & 7150-T77511 EXTRUSIONS
“S”-BASIS MINIMUM 7150-T77511 EXTRUSION PROPERTIES
in.
mm
0.040-0.249
(1.00-6.34)
0.250-0.499
(6.35-12.69)
0.500-0.749
(12.70-19.04)
0.750-2.000
(19.05-50.80)
Ultimate Tensile
Strength
L
LT
85 (594)
81 (566)
87 (608)
82 (573)
88 (615)
83 (580)
89 (622)
83 (580)
Tensile Yield
Strength
L
LT
78 (545)
74 (510)
82 (573)
76 (531)
83 (580)
79 (552)
84 (587)
78 (545)
Compressive
Yield Strength
L
LT
78 (545)
76 (531)
82 (573)
80 (559)
83 (580)
81 (566)
85 (594)
82 (573)
Elongation %
L
7
8
9
8
K lc , ksi √in .
(MPA √m )
T-L
T-L
-
-
-
21 (23.1)
17 (18.7)
(Max. area, 20 sq. in., Max. circle diameter, 10 in.)
7 1 5 0 - T 7 7
S T A T U S
Statistically based “A” and “B” design mechanical and physical properties are available in specific
thickness ranges upon inquiry.
Alcoa does not provide guidelines for user solution heat treatment and artificial aging to -T77
condition at the present time. For artificial age forming in an autoclave, “TAF-temper” condition
is available subject to inquiry.
Extruded stepped shapes are not available in 7150-T77511.
H I S T O R Y
Alcoa has pioneered the development of the -T77 temper, a high strength corrosion resistant temper
for Alloy 7150 plate and extrusions.
Before development of the -T77 temper, corrosion resistance could be improved by artificially aging
beyond the point of peak strength to a -T76 condition, which significantly reduced static strength.
PRODUCT SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE
ALCOA MILL PRODUCTS, INC.
P.O. BOX 8025 • BETTENDORF, IOWA 52722 • (800) 523-9596 • www.millproducts-alcoa.com